Novelties in Rhynchospora (Cyperaceae) from the Guianas

Strong, Mark T.

doi:10.2307/3393065

Cited by 18 publications

(62 citation statements)

References 2 publications

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“…Except for the occurrence of two stamens, all other characteristics were previously described for R. tenuis subsp. austro-brasiliensis (Koyama 1972;Strong 2006). Our results showed both R. enmanuelis and R. tenuis subsp.…”

Section: Discussionsupporting

confidence: 51%

“…described by Barros (1960). However, these were very different from the description of Rocha & Luceño (2002) and Strong (2006). In this last case the stylopodium appeared to be reduced to a mucro.…”

Section: Discussioncontrasting

confidence: 47%

“…austro-brasiliensis also showed overlapping of the values for all morphologic characters, including R. junciformis, except for shape of stylopodium in the last one. When our data on morphology were compared with the morphological features reported by Barros (1960), Koyama (1972), Rocha & Luceño (2002) and Strong (2006) all these species were found to share similar features. However, when our results on size and shape of achenes and stylopodium, number of terminal spikelets, karyotypic features and ISSR and R. enmanuelis with at least 68% similarity.…”

Section: Resultsmentioning

confidence: 99%

“…Our analysis The literature shows that Rhynchospora junciformis can be differentiated from other species of R. sect. Tenues based on the smaller number of spikelets in the tip of culms, morphology of achenes and stylopodium (Barros 1960;Rocha & Luceño 2002, Strong 2006. Samples collected in Anhanduí exhibited overlap of some morphological features, however this population was differentiated from the other taxa by number of spikelets (1-2), achene shape (rounded to oblate) and stylopodium length (0.38-0.43 mm).…”

Section: Discussionmentioning

confidence: 99%

“…(Kükenthal 1951;Koyama 1972;Rocha & Luceño 2002). Rhynchospora riparia and R. emaciata possess striking features that distinguish them from R. tenuis (Vanzela et al 2000;Rocha & Luceño 2002;Strong 2006). Although R. riparia was considered the variety R. tenuis var.…”

Section: Introductionmentioning

confidence: 99%

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Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implications

et al. 2012

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Species of Rhynchospora sect. Tenues are morphologically very similar. Rhynchospora tenuis complex is the most problematic species complex in this group and it concentrates entities of difficult delimitation, as is the case of R. tenuis, R. tenuis subsp. austro-brasiliensis and R. enmanuelis. Samples of these three taxonomic entities, besides R. junciformis and R. breviuscula (Dichromena), were analyzed in a comparative way using morphologic, cytogenetic and molecular tools. Despite of high morphological similarity between these taxa, R. tenuis was separated from R. tenuis subsp. austro-brasiliensis and R. enmanuelis according to chromosome numbers (2n = 4 and 2n = 18) and ISSR markers. The combined analysis of shape and size of achenes and stylopodium, number of spikelets, cytogenetic features and molecular markers suggest a clear proximity among Rhynchospora junciformis, R. tenuis subsp. austro-brasiliensis and R. enmanuelis, in relation to R. tenuis. These data indicate the need for a new taxonomic review of R. sect. Tenues, mainly to solve the status and nomenclatural situation of R. tenuis subsp. austro-brasiliensis and R. enmanuelis. Key words: cytotaxonomy, dysploidy, ISSR, holocentric chromosomes, Poales. ResumoAs espécies de Rhynchospora sect. Tenues são morfologicamente muito similares. O complexo Rhynchospora tenuis é o mais problemático e concentra entidades de difícil delimitação, como é o caso de R. tenuis, R. tenuis subsp. austro-brasiliensis e R. enmanuelis. Amostras dessas três entidades taxonômicas, além de R. junciformis e R. breviuscula (Dichromena), foram analisadas de modo comparativo usando análises morfológicas, citogenéticas e moleculares. Apesar da elevada similaridade morfológica entre esses taxa, R. tenuis foi separada de R. tenuis subsp. austro-brasiliensis e R. enmanuelis de acordo com os números cromossômicos (2n = 4 e 2n = 18) e marcadores ISSR. A análise combinada da forma e tamanho dos aquênios e estilopódio, número de espiguetas, características citogenéticas e de marcadores moleculares, sugere uma clara proximidade entre Rhynchospora junciformis, R. tenuis subsp. austro-brasiliensis e R. enmanuelis, em relação à R. tenuis. Além disso, esses dados indicam a necessidade de uma nova revisão taxonômica para R. sect. Tenues, principalmente para resolver o status e a situação nomenclatural de R. tenuis subsp. austro-brasiliensis e R. enmanuelis. Palavras-chave: citotaxonomia, disploidia, ISSR, cromossomos holocêntricos, Poales. Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implicationsCaracterização morfológica e genômica do complexo Rhynchospora tenuis (Cyperaceae) e suas implicações taxômicas

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Section: Discussionsupporting

confidence: 51%

Section: Discussioncontrasting

confidence: 47%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implications

et al. 2012

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Comparative floral anatomy of Rhynchospora consanguinea and Rhynchospora pubera (Cyperoideae, Cyperaceae)

2016

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Rhynchospora is one of the most species-rich genera of Cyperaceae and one of the few with entomophilous species. Considering the few anatomical studies of the genus, especially of the reproductive structures, this study comparatively analysed the anatomy of flowers of two representative species of Rhynchospora, R. consanguinea and R. pubera, including the floral vasculature and the anatomy of the style base, which is persistent with the fruit. Both species have congested inflorescences with light-coloured bracts and bisexual flowers, and phenolic idioblasts in the anthers and gynoecium, characteristics that suggest insect pollination. In R. consanguinea, the bisexual and the most proximal male flower has perianths, a new character state reported for the genus. The floral vasculature pattern is similar in both species, but differs from that previously described for Rhynchospora. In both species, there are two vascular bundles in the rachilla, which split into three receptacular bundles, the latter forming a vascular plexus where the bundles of stamens, gynoecium and ovule are connected. No lateral carpellary trace was observed, and the presence of the abaxial receptacular bundle was interpreted as a vestige of the tricarpellate ancestral condition. In the fruit of both species, the thickened style base (stylopodium) has a parenchyma with idioblasts containing phenolic compounds and idioblasts with helical or reticulate cell wall thickenings. The stylopodium is a homologous structure in the species of Rhynchospora and to other genera of Cyperoideae and evolved several times in the subfamily.

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Cyperaceae Raddianae: a nomenclatural and taxonomic study of the Cyperaceae published in G. Raddi’s Agrostografia brasiliensis

2010

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Novelties in Rhynchospora (Cyperaceae) from the Guianas

Cited by 18 publications

References 2 publications

Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implications

Morphological and genomic characterization of Rhynchospora tenuis complex (Cyperaceae) and its taxonomic implications

Comparative floral anatomy of Rhynchospora consanguinea and Rhynchospora pubera (Cyperoideae, Cyperaceae)

Cyperaceae Raddianae: a nomenclatural and taxonomic study of the Cyperaceae published in G. Raddi’s Agrostografia brasiliensis

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